docs: def _fetch_all(self):
          """
          Internal helper that fetches the ring from Redis, including any
          inactive nodes/replicas. Returns a list of tuples (start, replica,
          heartbeat, expired), where
          * start: start of the range for which the replica is responsible
          * replica: name of the replica
          * heartbeat: unix time stamp of the last heartbeat
          * expired: boolean denoting whether this replica is inactive
          """
  
          now = time.time()
          expiry_time = now - NODE_TIMEOUT
  
          data = self.conn.zrange(self.key, 0, -1, withscores=True)
  
          ring = []
  
          for node_data, heartbeat in data:
              start, replica = node_data.split(':', 1)
              ring.append((int(start), replica, heartbeat, heartbeat < expiry_time))
  
          ring = sorted(ring, key=operator.itemgetter(0))
  
          return ring